Lipid Screening for Kids Comes Under Fire

New recommendations from the National Heart, Lung, and Blood Institute (NHLBI) for dyslipidemia screening in adolescents lack the backing of strong evidence and may have been influenced by financial conflicts of interest among the authors, critics argued.

In an expert panel report released late last year, the NHLBI recommended screening all children, ages 9 to 11, with a nonfasting lipid panel. The institute also suggested screening certain high-risk children and teens, ages 2 to 8 and ages 12 to 16, with two fasting lipid panels. The guidance was endorsed by the American Academy of Pediatrics.

But the high evidence grades for the "extremely aggressive pediatric lipid recommendations are inaccurate and unjustified and ... the conflicts of interest reported by panel members are too substantial to ignore," according to Thomas Newman, MD, MPH, of the University of California San Francisco, and colleagues,

"In short," they wrote in a commentary in the August issue of Pediatrics, "these guidelines provide evidence that the NHLBI's new 'evidence-based' guideline process did not achieve its goals."

In another commentary, some of the panel members who drafted the recommendations fired back.

"Newman et al offer only opinion and rhetoric and provide little evidence to inform an evidence-based discussion," wrote Brian McCrindle, MD, MPH, of the Hospital for Sick Children in Toronto, three other panel members (including the chair), and the panel coordinator for the NHLBI.

One concern raised by Newman and colleagues is the large number of children who would be subject to the two fasting lipid panels. The guidance calls for such screening in children with the following:

Diabetes

Hypertension

Body mass index above the 95th percentile

Tobacco exposure

A parent with a total cholesterol level of 240 mg/dL or higher or known dyslipidemia

Finally, a parent, grandparent, aunt, or uncle who has had a stroke or coronary artery disease before age 55 for men and 65 for women

Roughly 30% to 40% of children would meet the criteria for two fasting lipid panels on the basis of the family history alone, Newman and colleagues wrote, noting that going to get blood drawn before breakfast on two separate occasions can be a hardship for most families.

In addition, the guidance provides a single cutoff for LDL cholesterol (130 mg/dL or higher) that would trigger a special diet and routine lipid screenings in boys and girls -- even though girls have higher lipid levels compared with boys -- and lacks a discussion of the potential harms that could come from more widespread lipid screening in adolescents, they argued.

The strongest criticism they had, however, was about the quality of the evidence used to support the recommendations.

The chain of evidence cited by the panel in their recommendations regarding screening for dyslipidemia and hypertension "contains weak links, notably the absence of even observational evidence or modeling to estimate the clinical event benefits of screening for and intervening on these risk factors in children," Newman and colleagues wrote.

"There is a vast difference between evidence to support a concept and the studies of clinical events, actual benefits, and harms over the ensuing decades, that would be needed for these guidelines to qualify as evidence-based," they wrote.

McCrindle and colleagues countered by saying, "The large, diverse, and complex evidence base that addresses cardiovascular risk beginning in childhood, and the absence of decades-long event-driven clinical trials, required consideration of substantial and consistent evidence from observational studies, developing a chain of evidence."

They concluded that a "large body of consistent and compelling evidence supports the imperative to screen lipids during childhood."

Newman and colleagues disagreed, stating that the recommendations are based on expert opinion and not strong evidence. In that case, they said, it becomes especially important to minimize "even the appearance of conflict of interest."

They noted, however, that the members of the NHLBI panel had numerous relationships with companies that make lipid-lowering drugs and lipid tests.

"That so many panel members with conflicts of interest were selected to draft the pediatric lipid guidelines undermines the credibility of both the guidelines and the process through which they were produced," they charged.

McCrindle and his co-authors said that Newman and colleagues "fail to acknowledge that the guideline development process was specified a priori and evidence-based, and potential conflicts of interest were declared and vetted throughout the process."

They stated that maintaining partnerships between academia and industry is necessary to produce evidence about the efficacy and safety of various lipid-lowering medications in children and teens.

"The remuneration received covered costs and time, without significant financial incentive," they wrote. "The lipid recommendations were approved by a strong consensus of the panel, the highest level of approval. To contest the integrity of panel members and their deliberations without evidence is unfair and uninformed."

Newman reported that he had no conflicts of interest. One of his co-authors has received research support from Amgen, Medtronic and Zoll, and has NIH funding to support research on targeting of cholesterol-lowering medications for prevention of cardiovascular disease.

McCrindle serves as a consultant to or advisory board member at Genzyme (Sanofi), Merck, and Abbott and as a data and safety monitoring board member at Medpace, and receives research funding from Schering Plough, AstraZeneca, and the NIH. His co-authors reported relationships with Merck, LipoScience, Genzyme, and Pfizer.

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